BIO 201 Lecture Notes - Lecture 29: Macrophage, Cdk Inhibitor, Necrosis
23 Apr 2017
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Document Summary
Not technically part of mitosis but is part of m phase. After chromatids separate and spindle breaks down, a contractile ring forms. Contractile ring tightens, eventually diving parent cell into two daughter cells. Experiment: depolymerize actin using cytochalasin d (fungus toxin) result: no cytokinesis, inhibit myosin atpase activity result: no cytokinesis. Conclusion: actin and myosin are both required for cytokinesis. Actin and myosin mediate contraction of contractile ring leading to cytokinesis. After chromatids separate and spindle breaks down, vesicles are transported to the plane of cell division. Vesicles fuse with each other, separating daughter cell cytoplasms. Vesicles carry polysaccharides for new cell wall. P53 stops cell cycle if dna is damaged: dna damage -> p53 phosphorylation (activation, p53 activates transcription of cdk inhibitor -> cdk cannot phosphorylate rb, rb continues to inhibit e2f. Necrosis: death due to acute damage or disease. Apoptosis/ programmed cell death: controlled cell suicide.
